If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

# Zero-order reaction (with calculus)

Deriving the integrated rate law for zeroth order reactions using calculus. How you can graph zero order rate data to see a linear relationship.

## Want to join the conversation?

• At Please can you give some other examples for zero order? • does this system of increased half life with increased concentration apply in any way to radioactive decay. Like is there any place in nuclear chemistry this is true like in this video. • hello everyone i have a doubt...in this video we're told that the increase in concentration of A doesn't affect the rate...but won't it be false if the reaction occurs in a closed container as it would lead to a greater pressure and thus the compression of the gas and thus increase in it's density....which will eventually increase the number of molecules in contact with the metal surface...??
(1 vote) • In my Chemistry book, it states that sublimation is normally a zero-order reaction or process, as the concentration of molecules that have sufficient energy to sublime is limited by the solid's surface area. My book states that the concentration of these molecules does not change when the amount of subliming substance decreases. However, I am struggling to understand one thing: if the amount of subliming substance decreases and the object gets smaller, wouldn't that have an effect on the surface area of the solid as well as a consequent effect on the rate of reaction? Why exactly is sublimation zero-order when clearly the surface area is variable in different instances? The only way for sublimation to be zero-order is if the solid is held in a sealed container and is under dynamic equilibrium with its vapor pressure. Am I correct about this? I would appreciate it greatly if someone could help me out about all this.
(1 vote) • Zero order reaction simply means that the rate of reaction is independent of concentration of reactants. And if you put a substance in a box then the change in its area will be negligibly small compared to the amount of gas evolved. for example if there is 1 mole of dry ice aka solid CO2 and 0.1 mole of it sublimes then evolved CO2 will have huge 2.27 litres volume compared to the volume of 0.1 moles of solid CO2 and the change in active surface area will be small so it can be said that rate of reaction is almost constant but will surely change if amount of surface area is decreased considerably but this is generally not the case under "normal" conditions.

"normal" refers to the usual temperature at which a particular reaction happens or is feasible.
• At , how can a reaction have a zero order while the molecularity can never be zero? Because the powers raised over the concentration in an elementary reaction while using rate law is equal to the stoichiometric coefficients of reactants and these coefficients can also never be zero. • If K is always the same regardless of concentration, and Rate = k, is K still the same over time as the reaction continues? Does time effect K?
(1 vote) • Hi - at 0.29 why is change[a]/change of time negative?
(1 vote) • At , is the integrated rate law used always the same for zero order reactions?
(1 vote) • At , we added more ammonia molecules but it did not affect the rate of reaction as the added molecules were not on ammonia surface.What if we added the extra molecules on the ammonia surface??Also, if we removed some molecules from the ammonia surface, will it decrease the rate of reaction??
(1 vote) • If more molecules of ammonia were on the platinum surface this would increase the reaction rate. This could be achieved by increasing the surface area of the platinum by using more platinum and/or by grinding it to a smaller particle size.

Conversely, decreasing the surface area of the platinum so that there were fewer ammonia molecules on the surface would decrease the reaction rate.
(1 vote)
• What's the highest order reaction possible?
(1 vote) 